Autologous Bone Marrow Transplantation - Blog Science Connections

Burkitt's Lymphoma Purging Assay 353
replicates in order to analyze the reproducibility of the assay. The estimated
average number of BL cells was one per flask (4 x 10 6 bone marrow cells) at the
lowest dilution. In 12 of 13 experiments, the estimated single cell seed was
sufficient in one to five of the triplicate samples to yield detectable outgrowth of
BL cells after 10 days of culture. The mean value of the three was used as final
result (Table 1). In three experiments (Table 2) only one of three of the triplicate
samples did grow, and these cultures were kept until day 21, at which time the
growth of BL cells was detectable in three more flasks.
The ability of BL cells to grow in culture may vary from one line to another
and from one experiment to another. Thus, as shown by the range in Table 1,
the absolute number of detectable BL cells varied at day 10. Nevertheless,
within the same experiment, the growth of BL cells was closely correlated to the
original number of BL cells added at day 0. This correlation indicates that for
Table 1. The Outgrowth of BL Cells in Liquid Cultures
Cell
Line
(no. of
experiments)
Characteristics
BL Cells (%)
1 in 10 6 1 in 4 x 106
BLg 3
(EBV-) 41% (5-98%) 26% (1-80%)
(n = 5) Caucasian
BL 2
(EBV-) 53% (6-100%) 49% (2-96%)
(n = 2) Caucasian
BL (EBV+) 38% (35-42%) 8% (0-16%)
1 7
(n = 2) North African
BL (EBV+) 70% (5-100%) 57% (1-100%)
9 9
(n = 4) Caucasian
Abbreviations: BL, Burkitt's lymphoma: EBV, Epstein-Barr virus.
Note: The numbers show the percentage of BL cells detected in cultures at day 10
by the ratio of BL cells to normal cells at the start. The results are means of three to five
parallel samples in each experiment. The values in parentheses show the range
observed in the different experiments.
Table 2. Optimal Detection of BL Cells in Long-term Liquid Culture
BL Cells (%)
Cell Line Day 10 Day 21
BL93 0, 0, 3 0, 60, 100
BL 0, 0, 46 0, 80, 100
1 7
BL99 0, 0, 2 0, 100, 100
Abbreviation: BL, Burkitt's lymphoma.
Note: Results are expressed in the percentage of BL cells at days 10 and 21 of the
culture in the triplicate flasks. The contamination was one BL cell in 4 x 10 s normal
ones at the start.